So what happens if the second dose arrives very (eg. many months) late? Can you start again and give 3?
And is there any chance all the partial immunities will catalyze resistant mutations?
And is there any chance all the partial immunities will catalyze resistant mutations?
> So what happens if the second dose arrives very (eg. many months) late? Can you start again and give 3?
WHO guidance on incomplete vaccine courses (pre-COVID): https://www.who.int/immunization/policy/Immunization_routine...
In almost all cases, the suggestion is "resume without repeating the previous dose". The only exceptions are typhoid and cholera vaccinations. I don't know what these suggestions are based upon, but the source is as close to expert consensus as it can go (the WHO has gotten a lot of flak on COVID, but I have never heard anyone seriously doubt its guidance on standard vaccinations).
> And is there any chance all the partial immunities will catalyze resistant mutations?
Apparently this doesn't even happen much for antibiotics ( https://jamanetwork.com/journals/jamainternalmedicine/articl... ), so I wouldn't worry about it happening for vaccines. See https://www.pnas.org/content/115/51/12878 for a comparison. If it were a major issue, it would just as well be an issue with fully delivered vaccination courses, as they don't offer 100% immunity either. The amount of mutations arising should still be proportional to the sick population (or, rather, to its total prevalence over time and population), and anything that reduces the latter should reduce the former. Any vaccine-immune mutation can just as easily come up before the vaccine, unless it hampers the virus so strongly that it is unviable until the evolutionary landscape has shifted. At that point, however, we're looking at a much simpler problem.
Stockpiling of vaccines is a method to obtain certainty that you can vaccinate on schedule. There are better methods of ensuring certainty, e.g. by supporting manufacturers as well as possible to meet schedules, analyze weaknesses in supply chains, trying to counter them early, etc.
The issue is the cost of maintaining the stockpile:
> she and her colleagues projected that frontloading vaccine doses would avert between 34 and 42 per cent more symptomatic coronavirus infections, compared with a strategy of keeping half the shipments in reserve.
What's the cost of delaying the second shot for some groups? It's certainly non-zero, but 34 to 42 percent less symptomatic infections is a lot of prevented infections (and death).
The cost-benefit analysis gives a clear conclusion: don't stockpile.
If the vial manufacturer has a covid outbreak at their facility and has to stop manufacturing for two weeks, your scheduled shipments aren't going to be on time.
As supply goes up, and we get past the priority recpients to the general public, it probably makes sense to reduce the stockpile requirement; some general public aren't going to come back for their second dose anyway, and more risk is appropriate for general public than high risk groups.
On the other hand, given how poorly essential workers are actually treated by our society, I doubt that's how things actually work. (See - senior hospital administrators getting vaccines ahead of front-line medical staff...)
Indeed, but even if 20% of people don't get their second shot on time and the impact of that is equal to them not being vaccinated at all (we don't know but likely the impact is smaller), even then the impact would be lower than stockpiling vaccines which increases the number of symptomatic infections by 34 to 42 percent.
> If the vial manufacturer has a covid outbreak at their facility and has to stop manufacturing for two weeks, your scheduled shipments aren't going to be on time.
That's precisely where the government can step in and ensure that antibiotics therapies are available to workers in those facilities as well as daily tests. Then it doesn't have to shut down.
> As supply goes up, and we get past the priority recpients to the general public, it probably makes sense to reduce the stockpile requirement
At that point it's less relevant which strategy you choose.
I think my worst case expectation is much worse than yours.
With a two week production shut down, I expect my corner of the world would not get new shipments for more than two weeks; higher priority places would be getting their previous orders filled before us, and we'd only get more once the backlog was filled. Also, I fully expect any production will take at least a week to be made public, so too late for an eager dosing regimine to start holding back.
Keep in mind, we're in winter, and winter storms often cause logistical problems.
The one dose efficacy data is too low confidence to make good decisions with. I'm open to the argument that it's better to use two doses to give two people one dose than to give one person two doses, but it would have been nice if that was trialed. There's also a related question of if you have a dose, if it's better to give that to a properly timed first dose recipient, or to give it to someone who hasn't received a dose yet. Again, there's not quality data; I would lean towards following the trial parameters.
> That's precisely where the government can step in and ensure that antibiotics therapies are available to workers in those facilities as well as daily tests.
Where has this suddenly competent government been for the past year? Yes, we expect a new executive in the US in a month, but the handoff takes time in normal conditions, and we have reason to believe this one will be more abrupt than many.
How do antibiotics help for covid?
How do daily tests help avert a shutdown when you can spread the disease while testing negative? One person could infect most of a shift of workers, given the right circumstances; more than one shift if they do handoff work to the next shift.
Supply chain workers for the vaccine aren't in the priority lists for the vaccine either. Anyway, covid isn't the only communicable disease possibility.
Hmm yeah that's a problem with the vaccine manufacturer. Ideally in such a scenario, the second doses get served first, after which the higher priority first doses get served.
> How do antibiotics help for covid?
Urgh my fault sorry, I meant antibodies not antibiotics. I tried to use them as example for something that has limited availability but allows to shorten disease durations.
> How do daily tests help avert a shutdown when you can spread the disease while testing negative?
Of course a shutdown is most effective and if done on a population scale it's bad for the pandemic. But daily tests do help to curb the spread.
In this circumstance as well, taking a chance is worth it. Even if the virus mutates, changing the mRNA vaccines shouldn’t take more than a week.
> In this circumstance as well, taking a chance is worth it.
Nope nope nope nope. This is the literal example of survivor bias. You can't look at the results and use them to inform prior behaviour. The vaccine could have had catastrophic side effects.
The last stage of the trial (which took three months) was not about if they were safe - but simply if they worked. Meaning, they were cleared to have minimal side effects, just unclear if it worked.
If you had approved people to choose to take the vaccine in August we could have had 50M people with shots already.
A lot of people have my skepticism that the main reason that the FDA didn't want to do that since it might be a bit of a media heartache for them, but so what. Even if you thought it would only work 20% of the time that 20% of the time it saves 100,000+ lives.
The three month time of phase III had nothing to do with safety. That long period was only used because it took that long time for enough people to catch Covid naturally for them to prove statistical effectiveness. In the current system, if Covid had been raging at an extreme rate they would have had enough positives in the control group after a month and ended the trial then. If it had been under control, it actually would have taken many more months to declare effectiveness even though the extra wait time would have shown no more data on safety.
Whether or not phase II was sufficient on its own they could have declared the vaccine probably safe a month after phase III began instead of after three months. This would have still saved 50,000 lives in the US at minimum.
Do you think there were a bunch of experimental vaccines just floating around on the . . . dark web? ... That's not how it works. The vaccine makers themselves have no interest in distributing unproven vaccines. I myself was highly confident (and posted such on HN) that we would have a successful coronavirus vaccine, based on the scientific information available early in the pandemic. But it wasn't a surety. You must have a randomized trial or you risk very very bad outcomes. Some experimental vaccines (e.g., dengue) actually make the viral infection worse. Some don't work at all (e.g., Sanofi's covid vaccine). Heck Sanofi's vaccine is likely the easiest to manufacture and distribute. If we followed your "plan", it would likely be that most got the ineffective Sanofi vaccine and we would be moving dead bodies around with bull dozers as "vaccinated" people failed to practice social distancing.
I'm under the impression that's precisely what the world governments did? There were bar charts going around saying that XX% of each country's supply commitments came from Pfizer or Astrazeneca or Moderna or whatever.
It would not only be costly to throw out the vaccines, but also stupid.
This is exactly what they did - funded by governments.
Example:
https://en.wikipedia.org/wiki/Operation_Warp_Speed
>The program promotes mass production of multiple vaccines, and different types of vaccine technologies, based on preliminary evidence, allowing for faster distribution if clinical trials confirm one of the vaccines is safe and effective. The plan anticipates that some of these vaccines will not prove safe or effective, making the program more costly than typical vaccine development, but potentially leading to the availability of a viable vaccine several months earlier than typical timelines.